Encoding Decoding Free Portable isn't the easiest file locker to use, but it offers plenty of strong features. Its major downfall is that the files only work inside of this program once they're locked. You'll probably be fine with this once you see all the program can do.
Since this is a portable program, there's no installation needed and you can take it with you on a USB drive. The program supports regular file importing and drag-and-drop importing, too. Even though its layout is something out of a '90s sci-fi film, don't mistake it for a cheesy program. Encoding Decoding Free Portable offers full encryption and decryption in seconds. When you're locking a file, it will give your password a score so you know just how easy it would be to guess. The only downside is that the program uses a proprietary format to lock things. If you decide not to use it any longer, all of your locked files will stay locked forever. Its powerful encryption and ease of use are enough for you to keep it around, though.
Encoding Decoding Free Portable offers one of the best ways to lock down your files. The fact that it's portable and can go wherever you go is just icing on the cake. Just make sure your friends and family use it if you're sending them sensitive files under lock and key.